Pinocembrin, known as 5,7-Dihydroxyflavanone or 2,3-Dihydro-5,7-dihydroxy-2-phenyl-4H-1-benzopyran-4-one, is a water insoluble flavanone compound with the following formula:

There is one chiral center in the structure of pinocembrin, and natural pinocembrin is in its S-configuration with [α]D15 being −45.3 (c, 0.9, acetone as solvent).
(S)-pinocembrin is a natural product extracted from propolis. It is also found in nut pines, eucalyptus leaves, acacia gum, and the like with low concentrations (Combined Chemical Dictionary 2004). Now pinocembrin can be obtained by synthesis and therefore in abundance (Yonghao Cheng, Yabo Duan, Yan Qi, Xiaoyun Guo, Yuanfeng Tong, Guanhua Du, Song Wu, chemical reagent, 2006 Vol. 28, No. 7:437).
It is reported in the literature that pinocembrin is sensitive to plenty of malignant bacteria and fungus, and shows a relatively good antibacterial effect especially on some drug resistant strains (Hyun Koo, Pedro L. Rosalen, Jaime A. Cuiy, Yong K. Park, and William H. Bowen, Antimicrob. Agents & Chemother. 2002, 46 (5), 1302-1309). CN200410037860.9 discloses Levo-pinocembrin has a good effect on cerebral apoplexy.
Pinocembrin has a low oral bioavailability for its water-insolubility and its relatively low oral absorption. Moreover, it is difficult to make it into an injection for its water-insolubility. Especially since the pharmaceutical formulations are required to release active agents quickly and exert effects rapidly when they are used to treat an acute disease such as cerebral apoplexy, the most common clinical method to treat the acute disorder is an intravenous injection. Therefore, solubility problem of pinocembrin must be solved first in order to obtain injectable dosage forms.
So it is urgent to obtain pharmaceutical formulations of pinocembrin with good water-solubility.